Piece of eight

" Finding Spanish coins on early American archeological sites is fairly common, especially in the South. The most commonly used coin was the 8 real or the Spanish dollar (real means royal in Spanish). This coin had a value of one dollar when circulating in America. Eight real coins were frequently cut into pie-shaped halves, quarters, eighths and sixteenths to make change. These were called ""pieces of eight"" (peso de ocho). Americans in the south and West Indies called these fractional parts ""bits"" or ""bit pieces.""
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